This is a continuation-in-part of my patent application filed May 5, 1970, bearing Ser. No. 11,112 (now abandoned) which was in turn a continuation-in-part of my application filed Jan. 8, 1968, Ser. No. 696,458 now abandoned. For many years tennis rackets have been constructed of wood and various techniques have evolved through the years for forming the wood in such a manner as to provide a racket having the desired shape and proper performance characteristics. Presently, wooden tennis rackets are made of laminated wood since this is the easiest way to form the various curves yet maintain the desired qualities of strength, weight and resilience. A major difficulty with wooden tennis rackets is that the wood looses its resilience if it becomes too dry or too moist and it is customary to keep wooden rackets in a press to assure that if they should absorb some moisture, they will not warp when they dry out. A further difficulty with wooden rackets is the fact that they are somewhat fragile and the head and the throat can easily be broken if subjected to more then just normal usage. While a laminated wood tennis racket can be constructed having generally good strength and resilience for forces imparted normal to the axis of the handle, a racket of this type has generally low torque characteristics. Unless the ball strikes the racket near the center of the strings, maximum force will not be imparted to the ball because the head will tend to twist about the axis of the handle. In fact, if the ball is struck near the edge of the stringed portion the player will generally feel a rather dull and lifeless response quite unlike that experienced when the ball is struck in the center of the strings. Such a response indicates the inability of the wooden racket to withstand abnormal forces, particularly torque, or to provide the same degree of resilience at all portions of the head and it is presently necessary for the player to concentrate on striking the ball with the center of the racket.
Attempts have been made in the past to construct a tennis racket of materials other than wood but most of such efforts have been unsuccessful. Recently, alloys have been developed which permit the manufacture of a light weight metal tennis racket, but such alloys require special treatment in many cases and the cost is generally quite high. Metal rackets currently offered for sale are not only more expensive than wood but are generally too flexible particularly in regard to torque. There have also been efforts to manufacture fiberglass tennis rackets but the general approach has been to rely upon the techniques formerly used in the construction of wooden tennis rackets and then to use the fiberglass only as an outer covering. In other words, the racket is a composite of wood, resin and fiberglass or sometimes metal and fiberglass. With such construction, the fiberglass is not a structural element of the racket but is only a covering to prevent the entry of moisture and to provide a decorative surface. The strength and resilience of the racket is still dependent upon the core material used and in the case of wood, the lamination techniques employed.